neiam /lambent-flex-c6

Ask the build for fewer processes than the runner will give

65e23ac · Gabriel Morell · 2026-09-16 18:34

3 files +28 -0

Message

{commit_body(@commit)}

modified .forgejo/workflows/firmware.yml

+28 −0

@@ -110,6 +110,27 @@ jobs:

110	110	set -euo pipefail
111	111	mkdir -p .home
112	112
	113	+ # `bash: fork: retry: Resource temporarily unavailable` killed run
	114	+ # #2 here. That is a process ceiling, not a build error: cargo and
	115	+ # ninja both default to one job per core, and an ESP-IDF build plus
	116	+ # a Rust codegen fan-out is hundreds of processes on a machine with
	117	+ # many of them. Whatever the ceiling turns out to be — a pids cgroup,
	118	+ # RLIMIT_NPROC, or memory — asking for less is the fix that does not
	119	+ # depend on knowing which.
	120	+ #
	121	+ # Four is deliberately modest. This build is dominated by one cold
	122	+ # ESP-IDF install and link, not by parallel compilation, so the cost
	123	+ # is small and the failure it avoids is total.
	124	+ cores=$(nproc)
	125	+ jobs=$(( cores > 4 ? 4 : cores ))
	126	+ echo "building with $jobs jobs (of $cores cores)"
	127	+
	128	+ # Printed rather than interpreted: if this still dies, these four
	129	+ # numbers say which ceiling it was, and reading them out of a log
	130	+ # beats guessing at it a second time.
	131	+ echo "host: nproc=$cores ulimit-u=$(ulimit -u) pids.max=$(cat /sys/fs/cgroup/pids.max 2>/dev/null \|\| echo n/a)"
	132	+ free -m 2>/dev/null \| head -2 \|\| true
	133	+
113	134	# As root, then chown back: the workspace belongs to whatever user
114	135	# the runner runs as, the image's own user is `esp`, and the two
115	136	# need not agree. Root can write either way, and the chown at the

@@ -131,6 +152,11 @@ jobs:

131	152	-e LAMBENT_FLEX_VERSION="$VERSION" \
132	153	-e HOST_UID="$(id -u)" \
133	154	-e HOST_GID="$(id -g)" \
	155	+ -e CARGO_BUILD_JOBS="$jobs" \
	156	+ -e NUM_JOBS="$jobs" \
	157	+ -e CMAKE_BUILD_PARALLEL_LEVEL="$jobs" \
	158	+ -e MAKEFLAGS="-j$jobs" \
	159	+ --pids-limit 8192 \
134	160	"$TOOLCHAIN_IMAGE" \
135	161	bash -euo pipefail -c '
136	162	# ESP-IDF builds with cmake and the image ships ninja but not

@@ -142,6 +168,8 @@ jobs:

142	168	apt-get install -y --no-install-recommends cmake >/dev/null
143	169	fi
144	170
	171	+ echo "container: ulimit-u=$(ulimit -u) pids.max=$(cat /sys/fs/cgroup/pids.max 2>/dev/null \|\| echo n/a) jobs=$CARGO_BUILD_JOBS"
	172	+
145	173	cargo build --release
146	174
147	175	mkdir -p dist

Parents: e6c7b44